The Revenue will never send messages about tax rebates by email. Photograph: Sarah Lee for the Guardian

Taxpayers are being warned to look out for scam emails claiming to be sent by HM Revenue & Customs, after almost 80,000 phishing messages about tax rebates were reported in 2012.

The emails state that HMRC has reviewed the recipient's tax return and found that they are in line for a rebate, then asks for personal details, including credit card or banking details, in order to make the refund.

However, HMRC will never email a taxpayer about a rebate, and posts out payment orders to those who are owed money. The Revenue lists examples of fake emails on its website, which consumers can check.

In 2012, HMRC took action to close down 522 illegal sites that had been sending out the messages, hosted in a number of countries including the US, Russia and Japan, as well as central and eastern Europe.

There was an increase in phishing emails after the HMRC deadline for self-assessment tax returns on 31 January 2012.

Gareth Lloyd, head of digital security for HMRC, urged customers to send on emails to phishing@hmrc.gsi.gov.uk so it could investigate them.

"HMRC do everything we can to ensure customers are safe online and we are working closely with other law enforcement agencies to target the criminals behind this serious crime," he said.